Automatic control for fluid brakes



July 16, 1935. E. c. HEss 2,008,393

, AUTOMATIC CONTROL FOR FLUID BRAKES Filed April 5, 1953 2 sheets-sheet 1 23 .y iy ./9:

July 1s, 1935; E. C, HESSA l 2,008,393

AUTOMATIC CONTROL FOR FLUID BRAKES Patented July 16,v 1935.v t

Edward C. Hess, Berlin,

Wis., assigner of onethirc t Emil Hess, and one-third to M; J. raul, both of Berlin, Wis. A

Application Aprn 5, 1933, smal No. 664,570' z claims. (Cl. ac3-.so

This invention appertains to vehicle brakes of the hydraulic type and has for one otits primary objects the 'provision of novel means forl giving'a suitable signal to the driver of` the ve 6 hicle, should a leak occur in any one ofthe brake cylinders, so that the driver of the vehicle can instantly take the necessary steps to remedy such condition. L

Another salient object ofV my invention is the 10 provisionof means, Whereby'should a leak occur vin any one of the brake cylinders, an electric circuit will be closed through Ya. signal light on the instrument board of the vehicle in plain View of the driver, an independent signal light being provided for each brake, so that the driver will be immediately notified as to which brake is not inproper working condition.

A furtherimportant object of my invention is the provision of a novel attachment 'for hy draulic brakes embodying novel'cylinder units interposed between each wheel brake and master cylinder, the cylinder units functioning to automatically cut olf the supply of iuid to a leaking brake from 'the master cylinder, so that loss of- :duid will only result in the leaky brake, thereby rendering 'the brakes on the other three wheels operative' during the interval of repairing the leaky brake.

A further important object oi' my invention is the provision of novel means vwhereby any partcular 'brake will be automatically cutoif from the master cylinder to prevent loss of iluid should v a leak occur thereinA and at the same time impart a signal to the driver of the vehicle to indic'ate such brake has been rendered inoperative/ r A further object of my invention is the provision of novel means whereby the fluid can be readilyby-passed around the oating pistonof my novel valve unit toY recharge' the brake cylinder after the leak has been repaired. 'A still furtherobject of my invention. is to provide a novel signal 'and valve attachment for I hydraulic vehicle brakes of the above character, which will be durable and eicient inv use,'one 45 4that will be simple and easy to manufacture and incorporated with a, hydraulic brake system at a 'small cost.

With these and other objects in view, -the` invention consists in the novel construction, arrangement and formation ofvparts, as will be hereinafter more specifically described, claimed and illustrated in the vaccompanying drawings, in which: v

Figure 1 is an enlarged longitudinal section through one -oi my novel valve and signal units the shut-off valve closed position. 'f Y Figure 2 is a transverse section through said unit taken substantially on the line 2--2 of Figbeing shown in its inoperative ure- 1, the shut-off valve being shown in its open 5 normal position in this View.

Figure 3 is a detail fragmentary sectional view taken on a. still larger scale'illustrating the novel construction of the insulated plug utilized in conjunction with the alarn' circuit. lo

Figure 4 is a longitudinal section through the resilient contact head carried by the floating pistn for engagement with said insulated contact` plug.

Figure 5 is a diagrammatic view illustrating 15 a. vehicle chassis intopplan, showing my improved valve and indicator units incorporated with the hydraulic brakes thereof.

Figure 6 is a diagrammatic view illustrating the electrical circuits for the Signal lights. 20

Y Figure 7 is a face view of the panel carrying the signal lights for the' different brake units.

Referring to the drawings in detail, `wherein similar referenceV characters designate the corresponding parts. throughout the several views,

ltheletter A generally indicates the chassis of a motor vehicle provided with hydraulic brakes B for the wheels I Il Voi? said vehicle.

The hydraulic brake system B is of substantially the ordinary type and has only been shown diagrammatically and includes the master cylinder II connected by means of iluid conductor pipes I2 with the brake cylinders (not shown) for thebrakedrums ofthe wheels Ill. Fluid is forced from the master cylinder IIto the brake cylinders through the medium pedal (not shown), Y In accordance with my invention, I interpose of i theusual foot 'in each iiuid` conductor pipe I2 between the master cylinder II and each brake cylinder one of 40 my` novel valve units Il. Each of these valve cylinders Ilembodiesa housing I5, which can be in the nature of a solid metal block bored out from one end to provide an interior cylinder or cylinder chamber I6. This cylinder chamber I6 45 receives the novel floating piston or valve I1. After the oatingpiston and valve unit II has been placed into the cylinder chamber, the same is closed .by a. removable plug I8 carrying a threaded :nipple I9 to which is detachably secured 50 the fluid conductor pipe leading from the master cylinder. By referring to Figure Lit can be seen that Y-the removable plug -is provided with an axial b01'e,s0 Vthat the iluid'conductor pipe'leading 55 l from the master cylinder will have communication with the piston chamber. The housing forwardly of the piston chamber I6 is provided with a reduced bore 2U, which also communicates with the piston chamber and the bore has 'threaded therein a nipple 2l to which is connected the fluid conductor p'ipeleading to the particular brake cylinder for onefjof the vehicle wheels.

Formed within the housing I is a longitudinally extending by-pass passageway 22, which has communication with the opposite ends of the brake cylinder on opposite sides of the floating cylinder through the medium of transverse passageways 23 and 24 respectively. Removable closure plugs 25 are carri-ed bythe housing for facilitating the cleaning of the valve and piston unit and for facilitating the forming of the various passageways within the housing.

l Referring more particularly to the floating piston and valve unit I1, it is to be noted that the same embodies a rod 26 having an annular enlargement 21 forme-d thereonadjacent to the rear end thereof. 4Slipp-ed on the rod '26 from the forwardend thereof against the enlargement 21 is the piston body 28, which is preferably formed from rubber or the like, and the same is provided with an lannular groove 29 intermediate its ends for facilitating the expansion and contraction thereof. After the piston body 28 has been placed into position, a sleeve 30 is inserted on the rod against which is placed the ported washer 3l. The piston body 28, the spacer sleeve 3G and the ported washer 3| are hel-d in position on the rod by means of a suitable nut 32.

The extreme forward end of the rod 25 has threaded thereon a resilient contact head 33, more clearly illustrated in Figure 4 of the drawings. The purpose of this contact head will be more fully described, but it is to be vnoted that the same embodies an interiorly threaded cap 34,

which receives the threaded end of the rod and rearwardly extending resilient split skirt forming resilient fingers.

Slipped upon the rear end of the rod 26 against the enlargement 21 is a ported washer 36 of the same construction as the washer 3|, and` the washer 36 is held on the rod by means of a nut 31.

In operation of my improved piston and valve unit, the valve 55 is closed and the valve 56 is opened, and when the brake pedal is depressed, the brake fluid will be forced into the rear end (right-hand side FgLJe 1) of the cylinder chamber I6 through the nipple I8. The fluid will fiow through the passageway 60 of the valve 56 against the floating piston I1. This will force the floating piston I1 forwardly. (to the left-hand side of Figure 1) forcing the fluid from out of the chamberthrough the nipple `2| into the brake cylinder (not shown) causing the application of the brake. Should a leak occur in the brake cylinder or between the brake cylinder and the valve unit, the loss of fluid from the front part (left-hand side of Figure 1) -of the cylinder chamber and the pressure of the uid acting on the rear of -the piston will force the piston forwardly moving the resilienticontact head 33 into the reduced bore 2 0 and when the piston has reached its extreme forward movement, the travel thereof will be stopped. Obviously, no loss of fluid can occur in rear of the piston and consequently, only a minimum amount of the fluid will be lost.

In connection. with` each i cylinder and valve unit. I provide novel means for giving a signal to the driver of the vehicle, when a leak occurs inA any .brake cylinder or forwardly of the traveling piston I1. This means includes the resilient contact head 33 previously described and a contact plug or pin 38 carried by each of the piston units. As shown in Figure 3, the contact plug `or pin is provided with a flat contact head 39 disposed in the'reduced bore 20 and in the path of the resilient contact head 33. kThe contact plug 38 is thoroughly insulated from the housing and the vehicle chassis by the use of washers 40 formed from insulation and a sleeve 4I formed of insulation which surrounds the said contact plug or pin. y In Figure 6 I have illustrated the wiring diagram for the entire brake system and it can be seen that a -source of electrical energy, such as a battery 42, is provided. 'I'his can be the ordinary storage battery of the vehicle. One terminal of the storage battery 42 is grounded to the vehicle chassis as at 43 andconsequentl each of the housings I5 is grounded to the battery in that the housings are secured by means of metal bolts to the chassis frame. An attaching lip 44 is formed on each housing to facilitate this attachment.

Arranged on the instrument panel of the vehicle or at any other preferred convenient point is an indicator panel 45 carrying lamp sockets for indicating lamps 45, 41, 48 and 49. By referring to Figures 6 and '1, it can be seen that an iridependent signal'lamp is provided for each vehicle brake and a suitable mark is placed on the panel above each lamp, so as to indicate to the driver which lamp is used with each brake. Electrically connected to each Contact plug pin 38 is an electrical conductor wire 5,0 and this wire leads to one terminal of its lamp socket and the other terminal of each lamp socket has connected thereto a wire 5I, which leads to the other terminal of the storage battery 42.

Obviously, when the resilient contact head 33 engages the contact plug 38, a circuit will be closed through the signal light provided for thatA particular brake cylinder. The lighting of this light will immediately disclose to the vehicle driver that the said brake is inoperative.

. Thus, from the foregoing, it can be seen that I have not only provided means for preventing undue loss from the system, so as to prevent al1 of the brakes from becoming inoperative, but I have also provided means whereby an effective signal will be given to the operator to indicate which one of his brakes is becoming inoperative. In connection with my improved cut-off valve and piston unit, I provide a simple and efficient means for permitting the recharging ofthe brake cylinder with fluid after repairs have been made thereto. This means includes the passageways 22, 23 and A24 and in connection with these passageways, I employ two cut-olf valves and 56. The cut-off valve 55 is located Within the passageway 23 and consists of a hollow sleeve having a port 51 therein for communication or registration with the longitudinal passageway 22. A head 58 is formed on the valve or cut-off 55, so that the same can be readily turned to permit the port 51 to be moved into and out of registration with said passageway 22. An indicator and holding spring 58 is carried by the head 58 and suitioY able indicating marks canbe employed on thev V type and is more clearly illustrated in Figure 2 of the drawings. This .plug valve 55 extenck transversely through the housing I5 and is provided with a diametrically extending passageway 60. When the plug valve 56 is in one position, communication is established from the nipple I9 to the floating piston unit I1 and when the same is in its other position, communication is cut of! between the nipple I9 and said floating piston.

Normally, both the cut-olf valves 55 and 56 are so disposed that communication will be established between the master cylinder and the nipple I9 and the floating piston and communication will be cut off between the bore 20 and the passageway 22. In case of a leak in a particular brake cylinder and after the repair thereof, the cut-ofi valves 55 and 56 are turned to the position shown in Figure 1 of' the drawings and consequently, fluid is permitted to by-pass around the floating piston into the brake cylinder to recharge the same. The recharging oi' the brake cylinder will tend to return the floating piston to its nor- 4mal position with the contact head 33 from out of engagement with the contact plug 38 in that the pressure of the fluid will be against the forward end (left-hand side Figure 6) of the floating piston I'I."

To permit the return of the floating piston to its normal position, it is necessary to allow the bleeding of the trapped iluid between the plugv valve 56 and the floating piston. This is accomplished by providing a bleed passageway 5I in the plug valve. 'I'he bleed passageway 6| is adapted to communicate with the piston chamber when the plug valve is in its cut-oil position as shown in Figure l. This passageway. opens out through the outer end of the plug valve, as shown lin Figure 2 of the drawings, and the passageway can After the brake cylinders have been recharged, the valves 55 and 56 are returned to their normal position and the devices function in their normal manner.Y

Changes in `details may be made without departing from the spirit or the scope of this invention, but what I claim as new is:-

1. In an'hydraulic controlled system, a fluid conductor, a housing disposed within the length of said fluid conductor having a chamber, a floating piston in said chamber capable of movement in both directions in said chamber under iniluence of the fluid, means lor by-passing the fluid from one end of the chamber to the other around said piston including a. passageway connectedv with the opposite ends of the chamber, a combined cut-off and bleed valve in said chamber at one side of the piston for controlling the flow of iluid into the chamber and the bleeding of fluid from said chamber between the piston and the valve to the exterior of the housing. s

2. In an hydraulic controlled system, a fluid conductor, a housing disposed within the length of said fluid conductor having a chamber, a. oating piston in said chamber capable of movement in both directions in said chamber under the iniluence of the fluid, said oating piston including a metallic piston rod, a flexible piston body secured to the rod intermediate the ends thereof and snugly engaging the walls of the chamber, and guide washers on the piston rod beyond the piston body engaging vthe walls of the chamber, a stationary contact carried by the housing and disposed at one end of the chamber, and a contact head carried by one end of the piston rod for engaging the stationary contact when the piston is forced to one end of the chamber, and means for by-passing the fluid from one end of the cham-- ber to the other around the piston.

EDWARD c. nnss'. 4o 

